Technology Short Take #13

Welcome to Technology Short Take #13. It’s been a while since my last Technology Short Take, and much has happened (vSphere 5 was announced, HP discontinued the TouchPad and webOS, and I announced my move to Denver). Here are a few data center technology-related links that stood out to me over the last few weeks. I hope you find something useful!

Networking

Servers

Storage

  • Sometimes it seems like people don’t fully understand the level of compatibility between FC and FCoE. This post by Vijay Swami provides a good review of the impact of FCoE on the average storage administrator—in most cases, no impact at all.
  • Erik Smith has a good review of the FC/FCoE connectivity options for EMC storage platforms in this post. It’s worth taking a quick look if you are interested in more detail on what sort of FCoE connectivity options are supported.
  • On the flip side, here’s information from Cisco on storage interoperability with UCS.
  • This two-part series by Itzik Reich on Citrix XenDesktop 5 with EMC VNX and FAST Cache is a good read, especially if you are considering XenDesktop for your VDI environment. Part 1 is here, and part 2 is here.
  • Here’s another look at the impact of FAST Cache on VDI workloads.

Virtualization

  • This post on application consolidation by Scott Drummonds is an old post (from January 2010), but it’s still a good one. In this post, Scott shares data from tests assessing the impact of consolidating sequential access workloads with random access workloads on the same datastore. The results of the tests underscore the importance of knowing the I/O profile of your workloads.
  • Here’s a workaround for using static MAC addresses that fall outside the normal range that vSphere allows.
  • Cormac Hogan has a great series of blog posts on new storage features in vSphere 5. Part 1 covers VMFS-5, part 2 discusses Storage vMotion, part 3 covers VAAI, and so forth. This is definitely worth reading. Of course, there is this vSphere 5 book slated to come out in early October that will discuss all these features, too…
  • I have a whole collection of posts by William Lam; he’s been on a roll: a summary of the updates to esxcli, information on enabling support for nested 64-bit and Hyper-V VMs, and information on enabling nested Fault Tolerance.

Security

  • I came across this article on how to protect Hyper-V hosts against ARP spoofing. Unless I’m mistaken—and that’s certainly very possible—I don’t think that the vSwitch/distributed vSwitch security policies around MAC address changes and forged transmits protect against ARP spoofing. Anyone have any additional information on how a VMware vSphere shop would protect against ARP spoofing? Is it even necessary?
  • Harley Stagner has a pretty good write-up of the Nexus 1000V Virtual Security Gateway (VSG). The VSG—and the Nexus 1000V, for that matter—are products in which I’m very interested, but just haven’t had the time to really spend with them. Perhaps in the future!

It’s time to wrap up now, but thanks for reading. Feel free to share any other interesting or useful links you’ve found, or any thoughts on the links I included here, in the comments.

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  1. RB’s avatar

    In response to your question on the ARP spoofing:

    vSphere’s MAC address impersonation setting on the vSwitch and DVS prevents a VM from sending a packet with a MAC source that is different than the one assigned to the vNIC in the VMX file of the VM.

    What you may be confusing it with is ARP Cache Poisoning, which is a layer-3 attack against an OS. The vShield App IP Spoof Guard feature can prevent that type of attack against a VM.